What types of samples need to be run for a risk assessment when TPH levels are above 10,000 ppm?

For a risk assessment when total petroleum hydrocarbons (TPH) levels exceed 10,000 parts per million (ppm), it is critical to analyze both BTEX (benzene, toluene, ethylbenzene, and xylene) and PAHs (polycyclic aromatic hydrocarbons). The presence of these compounds can indicate the level of contamination and potential health risks associated with petroleum products.

BTEX compounds are known for their volatility and are common in petroleum products, making them relevant in assessing immediate human health risks, particularly concerning air quality and inhalation exposure. On the other hand, PAHs are often associated with the breakdown of organic materials and can be indicative of more chronic exposure risks, as they are known carcinogens and can persist in the environment.

Including both BTEX and PAHs in the risk assessment ensures a comprehensive evaluation of the contamination. This dual approach allows for a more accurate determination of environmental and health risks, leading to appropriate remediation strategies. Therefore, running samples for both BTEX and PAHs is essential when TPH levels are high, allowing assessors to understand the full scope of potential environmental impacts and health hazards.